1. Field of the Invention
The present invention relates generally to the field of interactive television systems. More specifically, the present invention relates to systems and methods for synchronizing multiple signals transmitted via different means, such as, for example, a video signal transmitted via broadcast television and a secondary audio signal transmitted via the Internet.
2. Description of Related Background Art
Traditionally, both radio and television stations provide coverage for sporting events, such as football, basketball, baseball, etc. Indeed, multiple radio and television stations typically cover an event for both local and national audiences.
Although television offers the apparent advantage of allowing a person to see the sporting event, many prefer the radio for a number of reasons. For example, radio announcers often provide a better commentary since they must rely on words alone to describe the event. Moreover, radio broadcasts typically include fewer commercials, interviews, human interest stories, or the like, which tend to interrupt the event.
To obtain the advantages of both radio and television, some people watch a televised sporting event with the volume muted, while simultaneously listening to a radio commentary by their favorite announcer. As a result, the viewer obtains the benefits of better commentary, fewer interruptions, and the like, while also being able to watch the event. This approach is possible because television and radio broadcasts are typically received at same time with little or no relative delay.
Unfortunately, listening to radio coverage of a televised sporting event may not always be possible. For example, for events in remote cities, there may be no locally-broadcast radio coverage. In addition, a user may not be aware of which events are being broadcast on which radio stations.
Today, radio programs are beginning to be broadcast via the Internet. Radio signals are digitized, packetized, and transmitted to a receiver""s computer using standard protocols such as TCP/IP (transmission control protocol/Internet protocol). Various standard software programs are available for receiving and playing radio signals transmitted via the Internet, such as RealPlayer Plus(copyright), available from RealNetworks, Inc. of Seattle, Wash.
Advantageously, Internet-based radio transmissions are not geographically limited. Thus, a local radio station in New York City may be received via the Internet in Seattle or anywhere else in the world. It is now possible to choose from radio broadcasts from thousands of radio stations around the world via the Internet medium.
Unfortunately, the process including digitizing the radio signal, establishing a communication channel, and transmitting the radio signal via the Internet introduces a delay of several seconds when compared to a television signal broadcast, for example, via a cable network. Thus, the Internet-based radio coverage of a sporting event is delayed in time with respect to the television coverage, making a direct combination of the two undesirable due to lack of synchronization between the two signals.
What is needed, then, is a system and method for synchronizing a video program from television broadcast with a secondary audio program generated simultaneously with the video program. What is also needed is a system and method for replacing a primary audio program associated with a television broadcast with a second audio program. What is also needed is a system and method for allowing a user to easily select a secondary audio program to replace a primary audio program associated with a television broadcast.